Merge commit 'v1.7.6' into jc/checkout-reflog-fix

* commit 'v1.7.6': (3211 commits)
  Git 1.7.6
  completion: replace core.abbrevguard to core.abbrev
  Git 1.7.6-rc3
  Documentation: git diff --check respects core.whitespace
  gitweb: 'pickaxe' and 'grep' features requires 'search' to be enabled
  t7810: avoid unportable use of "echo"
  plug a few coverity-spotted leaks
  builtin/gc.c: add missing newline in message
  tests: link shell libraries into valgrind directory
  t/Makefile: pass test opts to valgrind target properly
  sh-i18n--envsubst.c: do not #include getopt.h
  Fix typo: existant->existent
  Git 1.7.6-rc2
  gitweb: do not misparse nonnumeric content tag files that contain a digit
  Git 1.7.6-rc1
  fetch: do not leak a refspec
  t3703: skip more tests using colons in file names on Windows
  gitweb: Fix usability of $prevent_xss
  gitweb: Move "Requirements" up in gitweb/INSTALL
  gitweb: Describe CSSMIN and JSMIN in gitweb/INSTALL
  ...

1 files changed, 782 insertions, 0 deletions

diff --git a/builtin/reflog.c b/builtin/reflog.c
new file mode 100644
index 0000000000..ebf610e64a
--- /dev/null
+++ b/builtin/reflog.c
@@ -0,0 +1,782 @@
+#include "cache.h"
+#include "builtin.h"
+#include "commit.h"
+#include "refs.h"
+#include "dir.h"
+#include "tree-walk.h"
+#include "diff.h"
+#include "revision.h"
+#include "reachable.h"
+
+/*
+ * reflog expire
+ */
+
+static const char reflog_expire_usage[] =
+"git reflog expire [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
+static const char reflog_delete_usage[] =
+"git reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
+
+static unsigned long default_reflog_expire;
+static unsigned long default_reflog_expire_unreachable;
+
+struct cmd_reflog_expire_cb {
+	struct rev_info revs;
+	int dry_run;
+	int stalefix;
+	int rewrite;
+	int updateref;
+	int verbose;
+	unsigned long expire_total;
+	unsigned long expire_unreachable;
+	int recno;
+};
+
+struct expire_reflog_cb {
+	FILE *newlog;
+	enum {
+		UE_NORMAL,
+		UE_ALWAYS,
+		UE_HEAD
+	} unreachable_expire_kind;
+	struct commit_list *mark_list;
+	unsigned long mark_limit;
+	struct cmd_reflog_expire_cb *cmd;
+	unsigned char last_kept_sha1[20];
+};
+
+struct collected_reflog {
+	unsigned char sha1[20];
+	char reflog[FLEX_ARRAY];
+};
+struct collect_reflog_cb {
+	struct collected_reflog **e;
+	int alloc;
+	int nr;
+};
+
+#define INCOMPLETE	(1u<<10)
+#define STUDYING	(1u<<11)
+#define REACHABLE	(1u<<12)
+
+static int tree_is_complete(const unsigned char *sha1)
+{
+	struct tree_desc desc;
+	struct name_entry entry;
+	int complete;
+	struct tree *tree;
+
+	tree = lookup_tree(sha1);
+	if (!tree)
+		return 0;
+	if (tree->object.flags & SEEN)
+		return 1;
+	if (tree->object.flags & INCOMPLETE)
+		return 0;
+
+	if (!tree->buffer) {
+		enum object_type type;
+		unsigned long size;
+		void *data = read_sha1_file(sha1, &type, &size);
+		if (!data) {
+			tree->object.flags |= INCOMPLETE;
+			return 0;
+		}
+		tree->buffer = data;
+		tree->size = size;
+	}
+	init_tree_desc(&desc, tree->buffer, tree->size);
+	complete = 1;
+	while (tree_entry(&desc, &entry)) {
+		if (!has_sha1_file(entry.sha1) ||
+		    (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
+			tree->object.flags |= INCOMPLETE;
+			complete = 0;
+		}
+	}
+	free(tree->buffer);
+	tree->buffer = NULL;
+
+	if (complete)
+		tree->object.flags |= SEEN;
+	return complete;
+}
+
+static int commit_is_complete(struct commit *commit)
+{
+	struct object_array study;
+	struct object_array found;
+	int is_incomplete = 0;
+	int i;
+
+	/* early return */
+	if (commit->object.flags & SEEN)
+		return 1;
+	if (commit->object.flags & INCOMPLETE)
+		return 0;
+	/*
+	 * Find all commits that are reachable and are not marked as
+	 * SEEN.  Then make sure the trees and blobs contained are
+	 * complete.  After that, mark these commits also as SEEN.
+	 * If some of the objects that are needed to complete this
+	 * commit are missing, mark this commit as INCOMPLETE.
+	 */
+	memset(&study, 0, sizeof(study));
+	memset(&found, 0, sizeof(found));
+	add_object_array(&commit->object, NULL, &study);
+	add_object_array(&commit->object, NULL, &found);
+	commit->object.flags |= STUDYING;
+	while (study.nr) {
+		struct commit *c;
+		struct commit_list *parent;
+
+		c = (struct commit *)study.objects[--study.nr].item;
+		if (!c->object.parsed && !parse_object(c->object.sha1))
+			c->object.flags |= INCOMPLETE;
+
+		if (c->object.flags & INCOMPLETE) {
+			is_incomplete = 1;
+			break;
+		}
+		else if (c->object.flags & SEEN)
+			continue;
+		for (parent = c->parents; parent; parent = parent->next) {
+			struct commit *p = parent->item;
+			if (p->object.flags & STUDYING)
+				continue;
+			p->object.flags |= STUDYING;
+			add_object_array(&p->object, NULL, &study);
+			add_object_array(&p->object, NULL, &found);
+		}
+	}
+	if (!is_incomplete) {
+		/*
+		 * make sure all commits in "found" array have all the
+		 * necessary objects.
+		 */
+		for (i = 0; i < found.nr; i++) {
+			struct commit *c =
+				(struct commit *)found.objects[i].item;
+			if (!tree_is_complete(c->tree->object.sha1)) {
+				is_incomplete = 1;
+				c->object.flags |= INCOMPLETE;
+			}
+		}
+		if (!is_incomplete) {
+			/* mark all found commits as complete, iow SEEN */
+			for (i = 0; i < found.nr; i++)
+				found.objects[i].item->flags |= SEEN;
+		}
+	}
+	/* clear flags from the objects we traversed */
+	for (i = 0; i < found.nr; i++)
+		found.objects[i].item->flags &= ~STUDYING;
+	if (is_incomplete)
+		commit->object.flags |= INCOMPLETE;
+	else {
+		/*
+		 * If we come here, we have (1) traversed the ancestry chain
+		 * from the "commit" until we reach SEEN commits (which are
+		 * known to be complete), and (2) made sure that the commits
+		 * encountered during the above traversal refer to trees that
+		 * are complete.  Which means that we know *all* the commits
+		 * we have seen during this process are complete.
+		 */
+		for (i = 0; i < found.nr; i++)
+			found.objects[i].item->flags |= SEEN;
+	}
+	/* free object arrays */
+	free(study.objects);
+	free(found.objects);
+	return !is_incomplete;
+}
+
+static int keep_entry(struct commit **it, unsigned char *sha1)
+{
+	struct commit *commit;
+
+	if (is_null_sha1(sha1))
+		return 1;
+	commit = lookup_commit_reference_gently(sha1, 1);
+	if (!commit)
+		return 0;
+
+	/*
+	 * Make sure everything in this commit exists.
+	 *
+	 * We have walked all the objects reachable from the refs
+	 * and cache earlier.  The commits reachable by this commit
+	 * must meet SEEN commits -- and then we should mark them as
+	 * SEEN as well.
+	 */
+	if (!commit_is_complete(commit))
+		return 0;
+	*it = commit;
+	return 1;
+}
+
+/*
+ * Starting from commits in the cb->mark_list, mark commits that are
+ * reachable from them.  Stop the traversal at commits older than
+ * the expire_limit and queue them back, so that the caller can call
+ * us again to restart the traversal with longer expire_limit.
+ */
+static void mark_reachable(struct expire_reflog_cb *cb)
+{
+	struct commit *commit;
+	struct commit_list *pending;
+	unsigned long expire_limit = cb->mark_limit;
+	struct commit_list *leftover = NULL;
+
+	for (pending = cb->mark_list; pending; pending = pending->next)
+		pending->item->object.flags &= ~REACHABLE;
+
+	pending = cb->mark_list;
+	while (pending) {
+		struct commit_list *entry = pending;
+		struct commit_list *parent;
+		pending = entry->next;
+		commit = entry->item;
+		free(entry);
+		if (commit->object.flags & REACHABLE)
+			continue;
+		if (parse_commit(commit))
+			continue;
+		commit->object.flags |= REACHABLE;
+		if (commit->date < expire_limit) {
+			commit_list_insert(commit, &leftover);
+			continue;
+		}
+		commit->object.flags |= REACHABLE;
+		parent = commit->parents;
+		while (parent) {
+			commit = parent->item;
+			parent = parent->next;
+			if (commit->object.flags & REACHABLE)
+				continue;
+			commit_list_insert(commit, &pending);
+		}
+	}
+	cb->mark_list = leftover;
+}
+
+static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
+{
+	/*
+	 * We may or may not have the commit yet - if not, look it
+	 * up using the supplied sha1.
+	 */
+	if (!commit) {
+		if (is_null_sha1(sha1))
+			return 0;
+
+		commit = lookup_commit_reference_gently(sha1, 1);
+
+		/* Not a commit -- keep it */
+		if (!commit)
+			return 0;
+	}
+
+	/* Reachable from the current ref?  Don't prune. */
+	if (commit->object.flags & REACHABLE)
+		return 0;
+
+	if (cb->mark_list && cb->mark_limit) {
+		cb->mark_limit = 0; /* dig down to the root */
+		mark_reachable(cb);
+	}
+
+	return !(commit->object.flags & REACHABLE);
+}
+
+static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct expire_reflog_cb *cb = cb_data;
+	struct commit *old, *new;
+
+	if (timestamp < cb->cmd->expire_total)
+		goto prune;
+
+	if (cb->cmd->rewrite)
+		osha1 = cb->last_kept_sha1;
+
+	old = new = NULL;
+	if (cb->cmd->stalefix &&
+	    (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
+		goto prune;
+
+	if (timestamp < cb->cmd->expire_unreachable) {
+		if (cb->unreachable_expire_kind == UE_ALWAYS)
+			goto prune;
+		if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
+			goto prune;
+	}
+
+	if (cb->cmd->recno && --(cb->cmd->recno) == 0)
+		goto prune;
+
+	if (cb->newlog) {
+		char sign = (tz < 0) ? '-' : '+';
+		int zone = (tz < 0) ? (-tz) : tz;
+		fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
+			sha1_to_hex(osha1), sha1_to_hex(nsha1),
+			email, timestamp, sign, zone,
+			message);
+		hashcpy(cb->last_kept_sha1, nsha1);
+	}
+	if (cb->cmd->verbose)
+		printf("keep %s", message);
+	return 0;
+ prune:
+	if (!cb->newlog || cb->cmd->verbose)
+		printf("%sprune %s", cb->newlog ? "" : "would ", message);
+	return 0;
+}
+
+static int push_tip_to_list(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
+{
+	struct commit_list **list = cb_data;
+	struct commit *tip_commit;
+	if (flags & REF_ISSYMREF)
+		return 0;
+	tip_commit = lookup_commit_reference_gently(sha1, 1);
+	if (!tip_commit)
+		return 0;
+	commit_list_insert(tip_commit, list);
+	return 0;
+}
+
+static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
+{
+	struct cmd_reflog_expire_cb *cmd = cb_data;
+	struct expire_reflog_cb cb;
+	struct ref_lock *lock;
+	char *log_file, *newlog_path = NULL;
+	struct commit *tip_commit;
+	struct commit_list *tips;
+	int status = 0;
+
+	memset(&cb, 0, sizeof(cb));
+
+	/*
+	 * we take the lock for the ref itself to prevent it from
+	 * getting updated.
+	 */
+	lock = lock_any_ref_for_update(ref, sha1, 0);
+	if (!lock)
+		return error("cannot lock ref '%s'", ref);
+	log_file = git_pathdup("logs/%s", ref);
+	if (!file_exists(log_file))
+		goto finish;
+	if (!cmd->dry_run) {
+		newlog_path = git_pathdup("logs/%s.lock", ref);
+		cb.newlog = fopen(newlog_path, "w");
+	}
+
+	cb.cmd = cmd;
+
+	if (!cmd->expire_unreachable || !strcmp(ref, "HEAD")) {
+		tip_commit = NULL;
+		cb.unreachable_expire_kind = UE_HEAD;
+	} else {
+		tip_commit = lookup_commit_reference_gently(sha1, 1);
+		if (!tip_commit)
+			cb.unreachable_expire_kind = UE_ALWAYS;
+		else
+			cb.unreachable_expire_kind = UE_NORMAL;
+	}
+
+	if (cmd->expire_unreachable <= cmd->expire_total)
+		cb.unreachable_expire_kind = UE_ALWAYS;
+
+	cb.mark_list = NULL;
+	tips = NULL;
+	if (cb.unreachable_expire_kind != UE_ALWAYS) {
+		if (cb.unreachable_expire_kind == UE_HEAD) {
+			struct commit_list *elem;
+			for_each_ref(push_tip_to_list, &tips);
+			for (elem = tips; elem; elem = elem->next)
+				commit_list_insert(elem->item, &cb.mark_list);
+		} else {
+			commit_list_insert(tip_commit, &cb.mark_list);
+		}
+		cb.mark_limit = cmd->expire_total;
+		mark_reachable(&cb);
+	}
+
+	for_each_reflog_ent(ref, expire_reflog_ent, &cb);
+
+	if (cb.unreachable_expire_kind != UE_ALWAYS) {
+		if (cb.unreachable_expire_kind == UE_HEAD) {
+			struct commit_list *elem;
+			for (elem = tips; elem; elem = elem->next)
+				clear_commit_marks(tip_commit, REACHABLE);
+			free_commit_list(tips);
+		} else {
+			clear_commit_marks(tip_commit, REACHABLE);
+		}
+	}
+ finish:
+	if (cb.newlog) {
+		if (fclose(cb.newlog)) {
+			status |= error("%s: %s", strerror(errno),
+					newlog_path);
+			unlink(newlog_path);
+		} else if (cmd->updateref &&
+			(write_in_full(lock->lock_fd,
+				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
+			 write_str_in_full(lock->lock_fd, "\n") != 1 ||
+			 close_ref(lock) < 0)) {
+			status |= error("Couldn't write %s",
+				lock->lk->filename);
+			unlink(newlog_path);
+		} else if (rename(newlog_path, log_file)) {
+			status |= error("cannot rename %s to %s",
+					newlog_path, log_file);
+			unlink(newlog_path);
+		} else if (cmd->updateref && commit_ref(lock)) {
+			status |= error("Couldn't set %s", lock->ref_name);
+		} else {
+			adjust_shared_perm(log_file);
+		}
+	}
+	free(newlog_path);
+	free(log_file);
+	unlock_ref(lock);
+	return status;
+}
+
+static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
+{
+	struct collected_reflog *e;
+	struct collect_reflog_cb *cb = cb_data;
+	size_t namelen = strlen(ref);
+
+	e = xmalloc(sizeof(*e) + namelen + 1);
+	hashcpy(e->sha1, sha1);
+	memcpy(e->reflog, ref, namelen + 1);
+	ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
+	cb->e[cb->nr++] = e;
+	return 0;
+}
+
+static struct reflog_expire_cfg {
+	struct reflog_expire_cfg *next;
+	unsigned long expire_total;
+	unsigned long expire_unreachable;
+	size_t len;
+	char pattern[FLEX_ARRAY];
+} *reflog_expire_cfg, **reflog_expire_cfg_tail;
+
+static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
+{
+	struct reflog_expire_cfg *ent;
+
+	if (!reflog_expire_cfg_tail)
+		reflog_expire_cfg_tail = &reflog_expire_cfg;
+
+	for (ent = reflog_expire_cfg; ent; ent = ent->next)
+		if (ent->len == len &&
+		    !memcmp(ent->pattern, pattern, len))
+			return ent;
+
+	ent = xcalloc(1, (sizeof(*ent) + len));
+	memcpy(ent->pattern, pattern, len);
+	ent->len = len;
+	*reflog_expire_cfg_tail = ent;
+	reflog_expire_cfg_tail = &(ent->next);
+	return ent;
+}
+
+static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (!strcmp(value, "never") || !strcmp(value, "false")) {
+		*expire = 0;
+		return 0;
+	}
+	*expire = approxidate(value);
+	return 0;
+}
+
+/* expiry timer slot */
+#define EXPIRE_TOTAL   01
+#define EXPIRE_UNREACH 02
+
+static int reflog_expire_config(const char *var, const char *value, void *cb)
+{
+	const char *lastdot = strrchr(var, '.');
+	unsigned long expire;
+	int slot;
+	struct reflog_expire_cfg *ent;
+
+	if (!lastdot || prefixcmp(var, "gc."))
+		return git_default_config(var, value, cb);
+
+	if (!strcmp(lastdot, ".reflogexpire")) {
+		slot = EXPIRE_TOTAL;
+		if (parse_expire_cfg_value(var, value, &expire))
+			return -1;
+	} else if (!strcmp(lastdot, ".reflogexpireunreachable")) {
+		slot = EXPIRE_UNREACH;
+		if (parse_expire_cfg_value(var, value, &expire))
+			return -1;
+	} else
+		return git_default_config(var, value, cb);
+
+	if (lastdot == var + 2) {
+		switch (slot) {
+		case EXPIRE_TOTAL:
+			default_reflog_expire = expire;
+			break;
+		case EXPIRE_UNREACH:
+			default_reflog_expire_unreachable = expire;
+			break;
+		}
+		return 0;
+	}
+
+	ent = find_cfg_ent(var + 3, lastdot - (var+3));
+	if (!ent)
+		return -1;
+	switch (slot) {
+	case EXPIRE_TOTAL:
+		ent->expire_total = expire;
+		break;
+	case EXPIRE_UNREACH:
+		ent->expire_unreachable = expire;
+		break;
+	}
+	return 0;
+}
+
+static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
+{
+	struct reflog_expire_cfg *ent;
+
+	if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
+		return; /* both given explicitly -- nothing to tweak */
+
+	for (ent = reflog_expire_cfg; ent; ent = ent->next) {
+		if (!fnmatch(ent->pattern, ref, 0)) {
+			if (!(slot & EXPIRE_TOTAL))
+				cb->expire_total = ent->expire_total;
+			if (!(slot & EXPIRE_UNREACH))
+				cb->expire_unreachable = ent->expire_unreachable;
+			return;
+		}
+	}
+
+	/*
+	 * If unconfigured, make stash never expire
+	 */
+	if (!strcmp(ref, "refs/stash")) {
+		if (!(slot & EXPIRE_TOTAL))
+			cb->expire_total = 0;
+		if (!(slot & EXPIRE_UNREACH))
+			cb->expire_unreachable = 0;
+		return;
+	}
+
+	/* Nothing matched -- use the default value */
+	if (!(slot & EXPIRE_TOTAL))
+		cb->expire_total = default_reflog_expire;
+	if (!(slot & EXPIRE_UNREACH))
+		cb->expire_unreachable = default_reflog_expire_unreachable;
+}
+
+static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
+{
+	struct cmd_reflog_expire_cb cb;
+	unsigned long now = time(NULL);
+	int i, status, do_all;
+	int explicit_expiry = 0;
+
+	default_reflog_expire_unreachable = now - 30 * 24 * 3600;
+	default_reflog_expire = now - 90 * 24 * 3600;
+	git_config(reflog_expire_config, NULL);
+
+	save_commit_buffer = 0;
+	do_all = status = 0;
+	memset(&cb, 0, sizeof(cb));
+
+	cb.expire_total = default_reflog_expire;
+	cb.expire_unreachable = default_reflog_expire_unreachable;
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
+			cb.dry_run = 1;
+		else if (!prefixcmp(arg, "--expire=")) {
+			cb.expire_total = approxidate(arg + 9);
+			explicit_expiry |= EXPIRE_TOTAL;
+		}
+		else if (!prefixcmp(arg, "--expire-unreachable=")) {
+			cb.expire_unreachable = approxidate(arg + 21);
+			explicit_expiry |= EXPIRE_UNREACH;
+		}
+		else if (!strcmp(arg, "--stale-fix"))
+			cb.stalefix = 1;
+		else if (!strcmp(arg, "--rewrite"))
+			cb.rewrite = 1;
+		else if (!strcmp(arg, "--updateref"))
+			cb.updateref = 1;
+		else if (!strcmp(arg, "--all"))
+			do_all = 1;
+		else if (!strcmp(arg, "--verbose"))
+			cb.verbose = 1;
+		else if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+		else if (arg[0] == '-')
+			usage(reflog_expire_usage);
+		else
+			break;
+	}
+
+	/*
+	 * We can trust the commits and objects reachable from refs
+	 * even in older repository.  We cannot trust what's reachable
+	 * from reflog if the repository was pruned with older git.
+	 */
+	if (cb.stalefix) {
+		init_revisions(&cb.revs, prefix);
+		if (cb.verbose)
+			printf("Marking reachable objects...");
+		mark_reachable_objects(&cb.revs, 0);
+		if (cb.verbose)
+			putchar('\n');
+	}
+
+	if (do_all) {
+		struct collect_reflog_cb collected;
+		int i;
+
+		memset(&collected, 0, sizeof(collected));
+		for_each_reflog(collect_reflog, &collected);
+		for (i = 0; i < collected.nr; i++) {
+			struct collected_reflog *e = collected.e[i];
+			set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
+			status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
+			free(e);
+		}
+		free(collected.e);
+	}
+
+	for (; i < argc; i++) {
+		char *ref;
+		unsigned char sha1[20];
+		if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
+			status |= error("%s points nowhere!", argv[i]);
+			continue;
+		}
+		set_reflog_expiry_param(&cb, explicit_expiry, ref);
+		status |= expire_reflog(ref, sha1, 0, &cb);
+	}
+	return status;
+}
+
+static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct cmd_reflog_expire_cb *cb = cb_data;
+	if (!cb->expire_total || timestamp < cb->expire_total)
+		cb->recno++;
+	return 0;
+}
+
+static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
+{
+	struct cmd_reflog_expire_cb cb;
+	int i, status = 0;
+
+	memset(&cb, 0, sizeof(cb));
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
+			cb.dry_run = 1;
+		else if (!strcmp(arg, "--rewrite"))
+			cb.rewrite = 1;
+		else if (!strcmp(arg, "--updateref"))
+			cb.updateref = 1;
+		else if (!strcmp(arg, "--verbose"))
+			cb.verbose = 1;
+		else if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+		else if (arg[0] == '-')
+			usage(reflog_delete_usage);
+		else
+			break;
+	}
+
+	if (argc - i < 1)
+		return error("Nothing to delete?");
+
+	for ( ; i < argc; i++) {
+		const char *spec = strstr(argv[i], "@{");
+		unsigned char sha1[20];
+		char *ep, *ref;
+		int recno;
+
+		if (!spec) {
+			status |= error("Not a reflog: %s", argv[i]);
+			continue;
+		}
+
+		if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
+			status |= error("no reflog for '%s'", argv[i]);
+			continue;
+		}
+
+		recno = strtoul(spec + 2, &ep, 10);
+		if (*ep == '}') {
+			cb.recno = -recno;
+			for_each_reflog_ent(ref, count_reflog_ent, &cb);
+		} else {
+			cb.expire_total = approxidate(spec + 2);
+			for_each_reflog_ent(ref, count_reflog_ent, &cb);
+			cb.expire_total = 0;
+		}
+
+		status |= expire_reflog(ref, sha1, 0, &cb);
+		free(ref);
+	}
+	return status;
+}
+
+/*
+ * main "reflog"
+ */
+
+static const char reflog_usage[] =
+"git reflog [ show | expire | delete ]";
+
+int cmd_reflog(int argc, const char **argv, const char *prefix)
+{
+	if (argc > 1 && !strcmp(argv[1], "-h"))
+		usage(reflog_usage);
+
+	/* With no command, we default to showing it. */
+	if (argc < 2 || *argv[1] == '-')
+		return cmd_log_reflog(argc, argv, prefix);
+
+	if (!strcmp(argv[1], "show"))
+		return cmd_log_reflog(argc - 1, argv + 1, prefix);
+
+	if (!strcmp(argv[1], "expire"))
+		return cmd_reflog_expire(argc - 1, argv + 1, prefix);
+
+	if (!strcmp(argv[1], "delete"))
+		return cmd_reflog_delete(argc - 1, argv + 1, prefix);
+
+	/* Not a recognized reflog command..*/
+	usage(reflog_usage);
+}